---
title: sort-classes
description: Maintain a consistent order of class members with this ESLint rule. Improve readability and make it easier to navigate through your class structures
shortDescription: Enforce sorted classes
keywords:
  - eslint
  - sort classes
  - class methods order
  - eslint rule
  - coding standards
  - code quality
  - javascript linting
  - class members sorting
---

import CodeExample from '../../components/CodeExample.svelte'
import Important from '../../components/Important.astro'
import CodeTabs from '../../components/CodeTabs.svelte'
import dedent from 'dedent'

Enforce sorted class members.

Organizing class members in a consistent order improves both readability and maintainability.

This rule helps developers quickly locate class members and understand the overall structure of the class.

By sorting class members systematically, confusion is minimized, and the code becomes more intuitive to navigate. This practice not only aids in individual productivity but also enhances team collaboration by establishing clear and predictable coding standards.

## Try it out

<CodeExample
  alphabetical={dedent`
    class User {
      constructor(username: string, email: string, isActive: boolean) {
        this.username = username
        this.email = email
        this.isActive = isActive
        this.roles = []
      }

      activate() {
        this.isActive = true
      }

      addRole(role: string) {
        this.roles.push(role)
      }

      deactivate() {
        this.isActive = false
      }

      getProfile() {
        return {
          username: this.username,
          email: this.email,
          isActive: this.isActive,
          roles: this.roles,
        }
      }

      removeRole(role: string) {
        this.roles = this.roles.filter(r => r !== role)
      }

      setEmail(newEmail: string) {
        this.email = newEmail
      }
    }
  `}
  lineLength={dedent`
    class User {
      constructor(username: string, email: string, isActive: boolean) {
        this.username = username
        this.email = email
        this.isActive = isActive
        this.roles = []
      }

      getProfile() {
        return {
          username: this.username,
          email: this.email,
          isActive: this.isActive,
          roles: this.roles,
        }
      }

      removeRole(role: string) {
        this.roles = this.roles.filter(r => r !== role)
      }

      setEmail(newEmail: string) {
        this.email = newEmail
      }

      addRole(role: string) {
        this.roles.push(role)
      }

      deactivate() {
        this.isActive = false
      }

      activate() {
        this.isActive = true
      }
    }
  `}
  initial={dedent`
    class User {
      constructor(username: string, email: string, isActive: boolean) {
        this.username = username
        this.email = email
        this.isActive = isActive
        this.roles = []
      }

      addRole(role: string) {
        this.roles.push(role)
      }

      deactivate() {
        this.isActive = false
      }

      setEmail(newEmail: string) {
        this.email = newEmail
      }

      activate() {
        this.isActive = true
      }

      removeRole(role: string) {
        this.roles = this.roles.filter(r => r !== role)
      }

      getProfile() {
        return {
          username: this.username,
          email: this.email,
          isActive: this.isActive,
          roles: this.roles,
        }
      }
    }
  `}
  client:load
  lang="tsx"
/>

## Options

This rule accepts an options object with the following properties:

### type

<sub>default: `'alphabetical'`</sub>

Specifies the sorting method.

- `'alphabetical'` — Sort items alphabetically (e.g., “a” < “b” < “c”) using [localeCompare](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/localeCompare).
- `'natural'` — Sort items in a [natural](https://github.com/yobacca/natural-orderby) order (e.g., “item2” < “item10”).
- `'line-length'` — Sort items by code line length (shorter lines first).
- `'custom'` — Sort items using the alphabet specified in the [`alphabet`](#alphabet) option.
- `'unsorted'` — Do not sort items. [`grouping`](#groups) and [`newlines behavior`](#newlinesbetween) are still enforced.

### order

<sub>default: `'asc'`</sub>

Specifies whether to sort items in ascending or descending order.

- `'asc'` — Sort items in ascending order (A to Z, 1 to 9).
- `'desc'` — Sort items in descending order (Z to A, 9 to 1).

### fallbackSort

<sub>
  type:
  ```ts
  {
    type: 'alphabetical' | 'natural' | 'line-length' | 'custom' | 'unsorted'
    order?: 'asc' | 'desc'
  }
  ```
</sub>
<sub>default: `{ type: 'unsorted' }`</sub>

Specifies fallback sort options for elements that are equal according to the primary sort
[`type`](#type).

Example: enforce alphabetical sort between two elements with the same length.
```ts
{
  type: 'line-length',
  order: 'desc',
  fallbackSort: { type: 'alphabetical', order: 'asc' }
}
```

### alphabet

<sub>default: `''`</sub>

Used only when the [`type`](#type) option is set to `'custom'`. Specifies the custom alphabet for sorting.

Use the `Alphabet` utility class from `eslint-plugin-perfectionist/alphabet` to quickly generate a custom alphabet.

Example: `0123456789abcdef...`

### ignoreCase

<sub>default: `true`</sub>

Specifies whether sorting should be case-sensitive.

- `true` — Ignore case when sorting alphabetically or naturally (e.g., “A” and “a” are the same).
- `false` — Consider case when sorting (e.g., “a” comes before “A”).

### specialCharacters

<sub>default: `keep`</sub>

Specifies whether to trim, remove, or keep special characters before sorting.

- `'keep'` — Keep special characters when sorting (e.g., “_a” comes before “a”).
- `'trim'` — Trim special characters when sorting alphabetically or naturally (e.g., “_a” and “a” are the same).
- `'remove'` — Remove special characters when sorting (e.g., “/a/b” and “ab” are the same).

### locales

<sub>default: `'en-US'`</sub>

Specifies the sorting locales. Refer To [String.prototype.localeCompare() - locales](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/localeCompare#locales).

- `string` — A BCP 47 language tag (e.g. `'en'`, `'en-US'`, `'zh-CN'`).
- `string[]` — An array of BCP 47 language tags.

### partitionByComment

<sub>default: `false`</sub>

Enables the use of comments to separate the class members into logical groups. This can help in organizing and maintaining large classes by creating partitions within the class based on comments.

- `true` — All comments will be treated as delimiters, creating partitions.
- `false` — Comments will not be used as delimiters.
- `RegExpPattern = string | { pattern: string; flags: string}` — A regexp pattern to specify which comments should act as delimiters.
- `RegExpPattern[]` — A list of regexp patterns to specify which comments should act as delimiters.
- `{ block: boolean | RegExpPattern | RegExpPattern[]; line: boolean | RegExpPattern | RegExpPattern[] }` — Specify which block and line comments should act as delimiters.

### partitionByNewLine

<sub>default: `false`</sub>

When `true`, the rule will not sort the members of a class if there is an empty line between them. This helps maintain the defined order of logically separated groups of members.

```ts
class User {
  // Group 1
  firstName: string;
  lastName: string;

  // Group 2
  age: number;
  birthDate: Date;

  // Group 3
  address: {
    street: string;
    city: string;
  };
  phone?: string;

  // Group 4
  updateAddress(address: string) {}
  updatePhone(phone?: string) {}

  // Group 5
  editFirstName(firstName: string) {}
  editLastName(lastName: string) {}
};
```

### newlinesBetween

<sub>type: `number | 'ignore'`</sub>
<sub>default: `'ignore'`</sub>

Specifies how to handle newlines between groups.

- `'ignore'` — Do not report errors related to newlines.
- `0` — No newlines are allowed.
- Any other number — Enforce this number of newlines between each group, and forbid newlines inside groups.

You can also enforce the newline behavior between two specific groups through the `groups` options.

See the [`groups`](#newlines-between-groups) option.

This option is only applicable when [`partitionByNewLine`](#partitionbynewline) is `false`.

### ignoreCallbackDependenciesPatterns

<sub>
  type: `string | string[] | { pattern: string; flags?: string } | { pattern: string; flags?: string }[]`
</sub>
<sub>default: `[]`</sub>

Specifies regexp patterns of function names that should ignore dependency sorting in their callback functions.

Example with `ignoreCallbackDependenciesPatterns: ['^computed$']`:

```ts
class User {
  fullName = computed(() => this.role + ' - ' + this.username);
  role = signal('admin');
  username = signal('John');
};
```

Without `ignoreCallbackDependenciesPatterns: ['^computed$']`, `role` and `username` would be sorted before `fullName` as it depends on them.

### groups

<sub>
  type: `Array<string | string[]>`
</sub>
<sub>
  default:
  ```
  [
    'index-signature',
    'static-property',
    'static-block',
    ['protected-property', 'protected-accessor-property'],
    ['private-property', 'private-accessor-property'],
    ['property', 'accessor-property'],
    'constructor',
    'static-method',
    'protected-method',
    'private-method',
    'method',
    ['get-method', 'set-method'],
    'unknown',
  ]
  ```
</sub>

Specifies a list of class member groups for sorting. Groups help organize class members into categories, prioritizing them during sorting.

Each class member will be assigned a single group specified in the `groups` option (or the `unknown` group if no match is found).
The order of items in the `groups` option determines how groups are ordered.

Within a given group, members will be sorted according to the `type`, `order`, `ignoreCase`, etc. options.

Individual groups can be combined together by placing them in an array. The order of groups in that array does not matter.
All members of the groups in the array will be sorted together as if they were part of a single group.

Predefined groups are characterized by a single selector and potentially multiple modifiers. You may enter modifiers in any order, but the selector must always come at the end.

#### Constructors
- Selector: `constructor`.
- Modifiers: `protected`, `private`, `public`.
- Example: `protected-constructor`, `private-constructor`, `public-constructor` or `constructor`.

#### Methods
- Selectors: `get-method`, `set-method`, `method`.
- Modifiers: `static`, `abstract`, `decorated`, `override`, `protected`, `private`, `public`, `optional`, `async`.
- Example: `private-static-accessor-property`, `protected-abstract-override-method` or `static-get-method`.

The `optional` modifier is incompatible with the `get-method` and `set-method` selectors.

The `abstract` modifier is incompatible with the `static`, `private` and `decorated` modifiers.

`constructor`, `get-method` and `set-method` elements will also be matched as `method`.

#### Accessors
- Selector: `accessor-property`.
- Modifiers: `static`, `abstract`, `decorated`, `override`, `protected`, `private`, `public`.
- Example: `private-static-accessor-property`, `protected-abstract-override-method` or `static-get-method`.

The `abstract` modifier is incompatible with the `static`, `private` and `decorated` modifiers.

#### Properties
- Selectors: `function-property`, `property`.
- Modifiers: `static`, `declare`, `abstract`, `decorated`, `override`, `readonly`, `protected`, `private`, `public`, `optional`, `async`.
- Example: `readonly-decorated-property`.

The `abstract` modifier is incompatible with the `static`, `private` and `decorated` modifiers.

The `declare` modifier is incompatible with the `override` and `decorated` modifiers.

The `function-property` selector will match properties whose values are defined functions or arrow-functions.
As such, the `declare` and `abstract` modifiers are incompatible with this selector.

The `async` modifier is reserved for the `function-property` selector.

#### Index-signatures
- Selector: `index-signature`.
- Modifiers: `static`, `readonly`.
- Example: `static-readonly-index-signature`.

#### Static-blocks
- Selector: `static-block`.
- Modifiers: No modifier available.
- Example: `static-block`.

#### Important notes

##### Scope of the `private` modifier
The `private` modifier will currently match any of the following:
- Elements with the `private` keyword.
- Elements with their name starting with `#`.

##### Scope of the `public` modifier
Elements that are not `protected` nor `private` will be matched with the `public` modifier, even if the keyword is not present.

##### The `unknown` group
Members that don’t fit into any group specified in the `groups` option will be placed in the `unknown` group. If the `unknown` group is not specified in the `groups` option,
the members will remain in their original order.

##### Behavior when multiple groups match an element

The lists of selectors and modifiers above are both sorted by importance, from most to least important.
In case of multiple groups matching an element, the following rules will be applied:

1. Selector priority: `constructor`, `get-method` and `set-method` groups will always take precedence over `method` groups.
2. If the selector is the same, the group with the most modifiers matching will be selected.
3. If modifiers quantity is the same, order will be chosen based on modifier importance as listed above.

Example 1:

```ts
abstract class Class {

    protected abstract get field();

}
```

`field` can be matched by the following groups, from most to least important:
- `abstract-protected-get-method` or `protected-abstract-get-method`.
- `abstract-get-method`.
- `protected-get-method`.
- `get-method`.
- `abstract-protected-method` or `protected-abstract-method`.
- `abstract-method`.
- `protected-method`.
- `method`.
- `unknown`.

Example 2 (The most important group is written in the comments):

```ts
abstract class Example extends BaseExample {

  // 'index-signature'
  [key: string]: any;

  // 'public-static-property'
  static instance: Example;

  // 'declare-protected-static-readonly-property'
  declare protected static readonly value: string;

  // 'static-block'
  static {
    console.log("I am a static block");
  }

  // 'public-property'
  public description: string;

  // 'public-decorated-property'
  @SomeDecorator
  public value: number;

  // 'public-decorated-accessor-property'
  @SomeDecorator
  public accessor value: number;

  // 'public-decorated-get-method'
  @SomeDecorator
  get decoratedValue() {
    return this._value;
  }

  // 'public-decorated-set-method'
  @SomeDecorator
  set decoratedValue(value: number) {
    this._value = value;
  }

  // 'public-decorated-get-method'
  @SomeDecorator
  get value() {
    return this._value;
  }

  // 'public-get-method'
  get value() {
    return this._value;
  }

  // 'public-set-method'
  set value(value: number) {
    this._value = value;
  }

  // 'protected-abstract-override-readonly-decorated-property'
  @SomeDecorator
  protected abstract override readonly _value: number;

  // 'protected-decorated-accessor-property'
  @SomeDecorator
  protected accessor _value: number;

  // 'protected-property'
  protected name: string;

  // 'protected-decorated-get-method'
  @SomeDecorator
  protected get value() {
    return this._value;
  }

  // 'private-decorated-property'
  @SomeDecorator
  private _value: number;

  // 'private-decorated-accessor-property'
  @SomeDecorator
  private accessor _value: number;

  // 'private-property'
  private name: string;

  // 'private-decorated-get-method'
  @SomeDecorator
  private get value() {
    return this._value;
  }

  // 'public-constructor'
  constructor(value: number) {
    this._value = value;
  }

  // 'public-static-method'
  static getInstance() {
    return this.instance;
  }

  // 'protected-static-method'
  protected static initialize() {
    this.instance = new Example(0);
  }

  // 'private-static-method'
  private static initialize() {
    this.instance = new Example(0);
  }

  // 'public-decorated-method'
  @SomeDecorator
  public decoratedMethod() {
    return this._value;
  }

  // 'public-method'
  public display() {
    console.log(this._value);
  }

  // 'protected-method'
  protected calculate() {
    return this._value * 2;
  }

  // private-function-property
  private arrowProperty = () => {};

  // 'private-method'
  private calculate() {
    return this._value * 2;
  }

  // private-function-property
  private functionProperty = function() {};
}
```

##### Newlines between groups

You may place `newlinesBetween` objects between your groups to enforce the newline behavior between two specific groups.

See the [`newlinesBetween`](#newlinesbetween) option.

This feature is only applicable when [`partitionByNewLine`](#partitionbynewline) is `false`.

```ts
{
  newlinesBetween: 1,
  groups: [
    'a',
    { newlinesBetween: 0 }, // Overrides the global newlinesBetween option
    'b',
  ]
}
```

### customGroups

<Important title="Migrating from the old API">
Support for the object-based `customGroups` option has been removed.

Migrating from the old to the current API is easy:

Old API:
```ts
{
  "key1": "value1",
  "key2": "value2"
}
```

Current API:
```ts
[
  {
    "groupName": "key1",
    "elementNamePattern": "value1"
  },
  {
    "groupName": "key2",
    "elementNamePattern": "value2"
  }
]
```
</Important>

<sub>
  type: `Array<CustomGroupDefinition | CustomGroupAnyOfDefinition>`
</sub>
<sub>default: `[]`</sub>

You can define your own groups and use regex for matching very specific class members.

A custom group definition may follow one of the two following interfaces:

```ts
interface CustomGroupDefinition {
  groupName: string
  type?: 'alphabetical' | 'natural' | 'line-length' | 'unsorted'
  order?: 'asc' | 'desc'
  fallbackSort?: { type: string; order?: 'asc' | 'desc' }
  newlinesInside?: number
  selector?: string
  modifiers?: string[]
  elementNamePattern?: string | string[] | { pattern: string; flags?: string } | { pattern: string; flags?: string }[]
  elementValuePattern?: string | string[] | { pattern: string; flags?: string } | { pattern: string; flags?: string }[]
  decoratorNamePattern?: string | string[] | { pattern: string; flags?: string } | { pattern: string; flags?: string }[]
}
```
A class member will match a `CustomGroupDefinition` group if it matches all the filters of the custom group's definition.

or:

```ts
interface CustomGroupAnyOfDefinition {
  groupName: string
  type?: 'alphabetical' | 'natural' | 'line-length' | 'unsorted'
  order?: 'asc' | 'desc'
  fallbackSort?: { type: string; order?: 'asc' | 'desc' }
  newlinesInside?: number
  anyOf: Array<{
      selector?: string
      modifiers?: string[]
      elementNamePattern?: string | string[] | { pattern: string; flags?: string } | { pattern: string; flags?: string }[]
      elementValuePattern?: string | string[] | { pattern: string; flags?: string } | { pattern: string; flags?: string }[]
      decoratorNamePattern?: string | string[] | { pattern: string; flags?: string } | { pattern: string; flags?: string }[]
  }>
}
```

A class member will match a `CustomGroupAnyOfDefinition` group if it matches all the filters of at least one of the `anyOf` items.

#### Attributes

- `groupName` — The group's name, which needs to be put in the [`groups`](#groups) option.
- `selector` — Filter on the `selector` of the element.
- `modifiers` — Filter on the `modifiers` of the element. (All the modifiers of the element must be present in that list)
- `elementNamePattern` — If entered, will check that the name of the element matches the pattern entered.
- `elementValuePattern` — Only for non-function properties. If entered, will check that the value of the property matches the pattern entered.
- `decoratorNamePattern` — If entered, will check that at least one `decorator` matches the pattern entered.
- `type` — Overrides the [`type`](#type) option for that custom group. `unsorted` will not sort the group.
- `order` — Overrides the [`order`](#order) option for that custom group.
- `fallbackSort` — Overrides the [`fallbackSort`](#fallbacksort) option for that custom group.
- `newlinesInside` — Enforces a specific newline behavior between elements of the group.

#### Match importance

The `customGroups` list is ordered:
The first custom group definition that matches an element will be used.

Custom groups have a higher priority than any predefined group. If you want a predefined group to take precedence over a custom group,
you must write a custom group definition that does the same as what the predefined group does (using `selector` and `modifiers` filters), and put it first in the list.

Example:

```js
 {
   groups: [
    'static-block',
    'index-signature',
+   'input-properties',                                     // [!code ++]
+   'output-properties',                                    // [!code ++]
    'constructor',
+   'unsorted-methods-and-other-properties',                // [!code ++]
    ['get-method', 'set-method'],
    'unknown',
   ],
+  customGroups: [                                          // [!code ++]
+    {                                                      // [!code ++]
+      // `constructor()` members must not match            // [!code ++]
+      // `unsorted-methods-and-other-properties`           // [!code ++]
+      // so make them match this first                     // [!code ++]
+       groupName: 'constructor',                           // [!code ++]
+       selector: 'constructor',                            // [!code ++]
+    },                                                     // [!code ++]
+    {                                                      // [!code ++]
+       groupName: 'input-properties',                      // [!code ++]
+       selector: 'property',                               // [!code ++]
+       modifiers: ['decorated'],                           // [!code ++]
+       decoratorNamePattern: 'Input',                      // [!code ++]
+    },                                                     // [!code ++]
+    {                                                      // [!code ++]
+       groupName: 'output-properties',                     // [!code ++]
+       selector: 'property',                               // [!code ++]
+       modifiers: ['decorated'],                           // [!code ++]
+       decoratorNamePattern: 'Output',                     // [!code ++]
+    },                                                     // [!code ++]
+    {                                                      // [!code ++]
+       groupName: 'unsorted-methods-and-other-properties', // [!code ++]
+       type: 'unsorted',                                   // [!code ++]
+       anyOf: [                                            // [!code ++]
+         {                                                 // [!code ++]
+            selector: 'method',                            // [!code ++]
+         },                                                // [!code ++]
+         {                                                 // [!code ++]
+            selector: 'property',                          // [!code ++]
+         },                                                // [!code ++]
+       ]                                                   // [!code ++]
+    },                                                     // [!code ++]
+  ]                                                        // [!code ++]
 }
```


## Usage

<CodeTabs
  code={[
    {
      source: dedent`
        // eslint.config.js
        import perfectionist from 'eslint-plugin-perfectionist'

        export default [
          {
            plugins: {
              perfectionist,
            },
            rules: {
              'perfectionist/sort-classes': [
                'error',
                {
                  type: 'alphabetical',
                  order: 'asc',
                  fallbackSort: { type: 'unsorted' },
                  ignoreCase: true,
                  specialCharacters: 'keep',
                  partitionByComment: false,
                  partitionByNewLine: false,
                  newlinesBetween: 'ignore',
                  ignoreCallbackDependenciesPatterns: [],
                  groups: [
                    'index-signature',
                    ['static-property', 'static-accessor-property'],
                    ['static-get-method', 'static-set-method'],
                    ['protected-static-property', 'protected-static-accessor-property'],
                    ['protected-static-get-method', 'protected-static-set-method'],
                    ['private-static-property', 'private-static-accessor-property'],
                    ['private-static-get-method', 'private-static-set-method'],
                    'static-block',
                    ['property', 'accessor-property'],
                    ['get-method', 'set-method'],
                    ['protected-property', 'protected-accessor-property'],
                    ['protected-get-method', 'protected-set-method'],
                    ['private-property', 'private-accessor-property'],
                    ['private-get-method', 'private-set-method'],
                    'constructor',
                    ['static-method', 'static-function-property'],
                    ['protected-static-method', 'protected-static-function-property'],
                    ['private-static-method', 'private-static-function-property'],
                    ['method', 'function-property'],
                    ['protected-method', 'protected-function-property'],
                    ['private-method', 'private-function-property'],
                    'unknown',
                  ],
                  customGroups: [],
                },
              ],
            },
          },
        ]
      `,
      name: 'Flat Config',
      value: 'flat',
    },
    {
      source: dedent`
        // .eslintrc.js
        module.exports = {
          plugins: [
            'perfectionist',
          ],
          rules: {
            'perfectionist/sort-classes': [
              'error',
              {
                type: 'alphabetical',
                order: 'asc',
                fallbackSort: { type: 'unsorted' },
                ignoreCase: true,
                specialCharacters: 'keep',
                partitionByComment: false,
                partitionByNewLine: false,
                newlinesBetween: 'ignore',
                ignoreCallbackDependenciesPatterns: [],
                groups: [
                  'index-signature',
                  ['static-property', 'static-accessor-property'],
                  ['static-get-method', 'static-set-method'],
                  ['protected-static-property', 'protected-static-accessor-property'],
                  ['protected-static-get-method', 'protected-static-set-method'],
                  ['private-static-property', 'private-static-accessor-property'],
                  ['private-static-get-method', 'private-static-set-method'],
                  'static-block',
                  ['property', 'accessor-property'],
                  ['get-method', 'set-method'],
                  ['protected-property', 'protected-accessor-property'],
                  ['protected-get-method', 'protected-set-method'],
                  ['private-property', 'private-accessor-property'],
                  ['private-get-method', 'private-set-method'],
                  'constructor',
                  ['static-method', 'static-function-property'],
                  ['protected-static-method', 'protected-static-function-property'],
                  ['private-static-method', 'private-static-function-property'],
                  ['method', 'function-property'],
                  ['protected-method', 'protected-function-property'],
                  ['private-method', 'private-function-property'],
                  'unknown',
                ],
                customGroups: [],
              },
            ],
          },
        }
      `,
      name: 'Legacy Config',
      value: 'legacy',
    },
  ]}
  type="config-type"
  client:load
  lang="tsx"
/>

## Version

This rule was introduced in [v0.11.0](https://github.com/azat-io/eslint-plugin-perfectionist/releases/tag/v0.11.0).

## Resources

- [Rule source](https://github.com/azat-io/eslint-plugin-perfectionist/blob/main/rules/sort-classes.ts)
- [Test source](https://github.com/azat-io/eslint-plugin-perfectionist/blob/main/test/sort-classes.test.ts)
